PDF Generator Guide

Introduction

This guide will walk you through the process of generating a simple PDF invoice you can send to your customers. It will also explain all the configuration options available in the “Generate PDF” workflow step. PDF invoices are valid for tax regimes that don’t require e-reporting or e-invoicing, and serves as a useful example from which to create your own workflows. Once completed, the workflow will work with any GOBL invoice produced for any country in the world.

Prerequisites

You’ll need the following data to issue basic PDF invoices:

Supplier details: fiscal details of the issuer.
Customer details: fiscal details of who is receiving for B2B invoices.
Items: list of products or services being sold, including quantities and prices.
Taxes & Rates: knowing how these apply to each item.
Series: a series is a counter with number formatting details to be able to generate a code.

Setup

Issuing PDF invoices with Invopop requires very little preparation. We assume that you already have access to the Invopop Console and know how to create a workflow.

Template
Code
Build from scratch

PDF Invoice workflow

Basic workflow to generate a PDF invoice

Copy and paste into a new Empty Invoice workflow code view.

Example PDF invoice workflow

{
  "name": "PDF invoice",
  "description": "Add a sequential code and generate a PDF",
  "schema": "bill/invoice",
  "steps": [
    {
      "id": "6b16c200-a75f-11ef-ba08-91f336761c6c",
      "name": "Add sequential code",
      "provider": "sequence.enumerate",
      "summary": "Dynamic · Invoice · 000001",
      "config": {
        "padding": 6,
        "start": 1,
        "name": "Invoice"
      }
    },
    {
      "id": "fc75e4f0-8721-11ef-a962-73e3f2037a52",
      "name": "Sign envelope",
      "provider": "silo.close"
    },
    {
      "id": "c61adaa0-7b55-11ef-bffc-d9a10ebf9f89",
      "name": "Generate PDF",
      "config": {
        "logo_height": 40,
        "locale": "en",
        "date_format": "%Y-%m-%d"
      },
      "summary": "English",
      "provider": "pdf"
    }
  ],
  "rescue": [
        {
            "id": "9a7b3d50-1358-11ef-af96-a18cfb3774fa",
            "name": "Set state",
            "config": {
                "state": "error"
            },
            "provider": "silo.state",
            "summary": "Set state to `error`{.state .error}"
        }
    ]
}

In Console create a new workflow and select Empty Invoice workflow in the template selector, then add the following steps:

Add sequential code - select the dynamic sequence option and set the name.
Sign envelope - signs the GOBL document, preventing further changes.
Generate PDF - configure the logo and language according to your needs.

Finally, in the Error Handling area, add the Set state action and select status Error.

Simple PDF Workflow — Example of the expected workflow

Configuration options

Once you have connected the “PDF Generator” app, you can configure the “Generate PDF” workflow step. The following options are available:

Content section


Upload logo	Upload an image which will be used as a logo in the document. A square or horizontal logo layout in PNG format is recommended. `PNG`, `GIF`, `JPG` and `SVG` file types are supported. For bitmap images, it is recommended that the logo is at least twice the size of the height for it to print in high quality. If you need to upload a different logo for each supplier, include the `logos` field in the party entry as detailed in the FAQ.
Logo height	Height for the logo in pixels. There’s 72 pixels in an inch and 37 pixels in a centimeter. The default height is 40 pixels (a little over 1cm)


Locale	Sets the language and formatting conventions used in the PDF. We add new locales based on the demand of our customers.
Date format	Controls how dates are displayed. Options include: `YYYY-MM-DD`, `DD-MM-YYYY`, `MM-DD-YYYY`, `DD.MM.YYYY`, `MM.DD.YYYY`
Time format	Controls how times are displayed in datetime fields. Options include: `20:45` (24-hour hh:mm), `20:45:03` (24-hour hh:mm:ss), `8:45 PM` (12-hour hh:mm), `8:45:00 PM` (12-hour hh:mm:ss). When set, the date and time are joined with a `·` separator.
Layout	Defines the physical page size for regional printing standards. Options include: `A4`: used in Europe and various other countries. `Letter`: used in United States, Canada, Mexico, Philippines, and other countries in Latin America. `DIN5008`: used in Germany as the standard for documents that will present information within an envelope window. If you select this option, the customer’s information (name and address) will be placed within this window.


Title badge	Contextual labels such as “original”, “copy”, “draft”, or “internal”
Background watermark	Text that will be displayed in the background of the document such as “draft”, “review”, “internal”, “confidential”, etc.


Hide “Powered by Invopop”	Toggle to hide the “Powered by Invopop” attribution. This setting does not remove the GOBL logo from the PDF.
Disable public download URLs	Security control to disable the creation of public download URLs for generated PDFs, preventing external sharing via link.
Adjustment invoices	Toggle to generate “adjustment invoices” using negative values instead of traditional credit and debit notes. Useful for countries that don’t officially recognise the concept of credit or debit notes such as Spain and Poland as detailed in the FAQ.
Flag as duplicate	Use when you want to generate a duplicate invoice. If not selected and the silo entry already contains a PDF, the workflow will overwrite the existing PDF.

Currency section

Currency formatting allows overriding the default currency formatting normally dictated by the document’s own currency.


Currency template	Whether the currency symbol should be before or after the number, e.g. `€100` or `100€`.
Format for negative values	Whether the negative sign should be before or after the number, e.g. `€-100` or `-€100`. Parenthesis `- €(100)` can also be used according to some accounting standards.
Thousands separator	Separator to improve the readability of the number, e.g. `1,000`, `1.000`, `1 000` or `1_000`.
Decimal mark	Separator for the decimal part of the number, e.g. `1.00` or `1,00`.

Workflow args

All configuration options above can also be set programmatically using workflow step args. This is useful when you need to dynamically override PDF settings per job via the API.

Arg Key	Type	Description
`pdf-logo-url`	string	URL of the supplier logo. Supports regular URLs and data URLs.
`pdf-logo-height`	integer	Height of the logo in pixels (default: 40).
`pdf-locale`	string	Two-letter language code, e.g. `en`, `es`, `de`.
`pdf-date-format`	string	Date format using `%Y`, `%m`, `%d` tokens, e.g. `%d/%m/%Y`.
`pdf-time-format`	string	Time format using `%H`, `%M`, `%S` (24-hour) or `%I`, `%M`, `%S`, `%p` (12-hour) tokens, e.g. `%H:%M` or `%I:%M %p`.
`pdf-layout`	string	Page layout: `A4`, `Letter`, or `DIN5008`.
`pdf-label`	string	Title badge text, e.g. `Paid`, `Original`.
`pdf-watermark`	string	Background watermark text, e.g. `Draft`, `Confidential`.
`pdf-hide-promo`	boolean	Set to `true` to hide the “Powered by Invopop” text.
`pdf-adjustment-mode`	boolean	Set to `true` to use negative amounts in credit notes.
`pdf-duplicate`	boolean	Set to `true` to generate a duplicate PDF without overwriting the existing one.

Running

Use the following example GOBL Invoices inside the Invopop Console or via the API to create new silo entries. Once a silo entry has been stored, you can create a new job to run the “PDF Invoice” workflow you just created.

B2B Invoice - United Kingdom

A simple invoice for a VAT registered supplier in the United Kingdom

{
  "$schema": "https://gobl.org/draft-0/bill/invoice",
  "currency": "GBP",
  "series": "TEST",
  "supplier": {
    "tax_id": {
      "country": "GB",
      "code": "844281425"
    },
    "name": "BrightTech Solutions Ltd.",
    "emails": [
      {
        "addr": "billing@brighttech.co.uk"
      }
    ],
    "addresses": [
      {
        "num": "123",
        "street": "Innovation Park",
        "locality": "Cambridge",
        "code": "CB1 2AB",
        "country": "GB"
      }
    ]
  },
  "customer": {
    "tax_id": {
      "country": "GB",
      "code": "350983637"
    },
    "name": "GreenWave Energy Ltd.",
    "emails": [
      {
        "addr": "info@greenwave.co.uk"
      }
    ],
    "addresses": [
      {
        "num": "45",
        "street": "Riverside Business Park",
        "locality": "London",
        "code": "SW1A 1AA",
        "country": "GB"
      }
    ]
  },
  "lines": [
    {
      "quantity": 50,
      "item": {
        "name": "Thermal efficient mugs",
        "price": "16.00"
      },
      "taxes": [
        {
          "cat": "VAT",
          "rate": "standard"
        }
      ]
    }
  ]
}

B2B Invoice - United States

Simple invoice for a VAT registered supplier in the United States

{
  "$schema": "https://gobl.org/draft-0/bill/invoice",
  "series": "SAMPLE",
  "currency": "USD",
  "tax": {
    "prices_include": "ST"
  },
  "supplier": {
    "name": "Provide One Inc.",
    "tax_id": {
      "country": "US"
    },
    "addresses": [
      {
        "num": "16",
        "street": "Jessie Street",
        "locality": "San Francisco",
        "region": "CA",
        "code": "94105",
        "country": "US"
      }
    ],
    "emails": [
      {
        "addr": "billing@provideone.com"
      }
    ]
  },
  "customer": {
    "name": "Sample Consumer",
    "emails": [
      {
        "addr": "email@sample.com"
      }
    ]
  },
  "lines": [
    {
      "i": 1,
      "quantity": "20",
      "item": {
        "name": "Development services",
        "price": "90.00",
        "unit": "h"
      },
      "discounts": [
        {
          "percent": "10%",
          "reason": "Special discount"
        }
      ],
      "taxes": [
        {
          "cat": "ST",
          "percent": "8.5%"
        }
      ]
    }
  ]
}

Example PDF invoices

Complete invoice (en)

Example PDF invoice Full invoice — View PDF

Belgian invoice (fr)

Example PDF invoice - Belgian invoice in French — View PDF

Colombian invoice (es)

Example PDF invoice - Colombian invoice in Spanish — View PDF

Greek invoice (el)

Example PDF invoice - Greek invoice in Greek — View PDF

Mexican invoice (es)

Example PDF invoice - Mexican invoice in Spanish — View PDF

Portuguese invoice (pt)

Spanish VERI*FACTU invoice (es)

Basque Country TicketBAI invoice (eu)

FAQ

How can I add a different logo for each supplier?

Add it to the supplier object within a logos array, the first logo in the array will be used. Make sure the “Generate PDF” step not configured with a logo, as it will override the supplier’s logo.

    "supplier": {
        "name": "Invopop SL",
        "tax_id": {
            "country": "ES",
            "code": "B85905495"
        },
        "logos": [
            {
                "url": "https://assets.invopop.com/logo.png",
                "height": 100,
                "width": 100
            }
        ]
    }

If the logo is not displayed, make sure your image is publicly accessible. Sometimes server restrictions prevent our services from accessing the image. An convenient way to verify that your image is publicly accessible is by asking an AI assistant “is this URL https://… publicly accesible?”.

Why would I want to use adjustment invoices?

Spain, along with a very small selection of other countries like Poland, doesn’t officially recognise the concept of credit or debit notes. Instead they use the concept of corrective or adjustment invoices whereby the amounts are displayed as differences from the original document. The two main types are:

Replacement Invoice (Factura Rectificativa por Sustitución) known in GOBL with the invoice type corrective and completely replaces any previous documents.
Adjustment Invoice (Factura Rectificativa por Diferencias) reflected in GOBL as either a credit-note or debit-note invoice type that appends to the previous documents.

GOBL is a designed to be an international format, so when deciding the types we try to take the most common business concepts and map them to local requirements. A credit note by definition implies a deduction from the preceding invoice, so all totals and values must be positive. This can cause confusion in Spain, where most companies are accustomed to the local way of issuing invoices with negative totals.When converting GOBL to the local tax agency format (like VERI*FACTU XML in Spain), Invopop will automatically inverts the values in a credit-note to ensure that the agency receives what they are expecting, while at the same time maintaining global compatibility in the actual document. With these changes, PDF can now apply the same logic to invert the totals and change the text translations while maintaining the same underlying information.

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Networks

Countries

Set-up

GOBL

Apps

API

Features

PDF Generator Guide

Introduction

Prerequisites

Setup

PDF Invoice workflow

Configuration options

Content section

Currency section

Workflow args

Running

Example PDF invoices

FAQ

Participate in our community

​Introduction

​Prerequisites

​Setup

PDF Invoice workflow

​Configuration options

​Content section

​Currency section

​Workflow args

​Running

​Example PDF invoices

​FAQ

Participate in our community

Introduction

Prerequisites

Setup

Configuration options

Content section

Currency section

Workflow args

Running

Example PDF invoices

FAQ